Consider an experiment where an Electric current is flowing in a wire. It is observed that a clockwise magnetic field is produced around the wire. A teacher decides to reverse the direction of the source battery which results in the reversal of electrical current. What will be the effect on the magnetic field?

If a clockwise magnetic field is produced around the wire. When we reverse the direction of the source battery it results in the reverse direction of the electrical current. Then the direction of  the magnetic field also reverses 

The direction of the magnetic field produced by the current-carrying wire depends on the direction of the current in the wire. Magnetic field patterns due to straight current-carrying conductors are concentric circles whose center lies on the wire. 
Using the Right-Hand thumb rule, as the current direction reverses, you need to reverse the hand, and the direction of the magnetic field reverses.